OBJECTIVE: to determine whether a low fat, high fiber, high vegetable and fruit eating plan will decrease the recurrence of adenomatous polyps of the large bowel.BACKGROUND: In the PPT, three dietary factors are being investigated simultaneously through intervention with a realistic, comprehensive dietary pattern change. Large bowel adenomas present a unique opportunity to conduct an intervention trial because of the high prevalence of these lesions, the high recurrence rate, and the fact that adenomas are considered precursors for most large bowel cancers. METHODS: Men and women with one or more adenomas recently removed were randomized at eight Clinical Centers between June 1991 and January 1994. The goals for the intervention group are 20% of calories from fat, 18g fiber/1000 kcal, and 5-8 servings of fruits and vegetables (the exact number based on caloric intake). The intervention program integrates nutrition education and behavior modification techniques. Participants in the control group are expected to maintain their usual diet. The PPT found no effect of the intervention diet on the recurrence of colorectal adenomatous polyps. Particpants from this trial have been recrutied into the PPT Continued Follow-up Study. We are collecting data on polyp recurrence and diet. Participants will be followed until April 2004.